Throat plate for book stitching machines



lune 27,1933. CysCl-{RAMM 1,915,551

THROAT PLATE FOR BOOK STITCHING MACHINES Filed July 28, 1932 yPatented .une '27, 1933 UNITED STATES PATENT omet CARL sCIIRAMM, or SOUTH CpvnaTRY, CONNECTICUT, AssIeNoR To Trany` vsairYzIiI MANUFACTURING COMPANY, OF HARTFORD, CONNECTICUT, A CORPORATION or i:

CONNECTICUT THROAT PLATE FOR BooK STITCHING MACHINES Application mea Iuiy as,

This invention relates to machines for stitching together the signatures of books, and more especially to the throat plates of stitching machines of the i straight-needle type. In Athese machines the signatures are carried automaticaly to the needles, .loopers, hooks and carriers which form thel stitches that fasten the folded edges of the signatures together. Then all of the signatures of a book are stitched it is necessary to cut the threads in order that the signatures of that book may be separated from the signatures of the following book. This has commonly been done by a cutter in the hands of an operative, mechanisms `having also been proposed for cutting the threads automatically. Besides the expense, operatives are liable to cut the threads between the wrong signatures, and with the prior automatic cutters it has been necessary in order to prevent the loosening -of the threads and separation of the end signatures to form an eXtra or locking stitch between the signatures of each book, and this interrupts vthe regular, continuous feed of the signatures with a corresponding decrease in the output.

The object of the present invention is to rovide means which will cause the severance of the threads between the books without interrupting the regular continuous feed of the signatures and without danger of cutting the wrong threads or allowing the end signatures of the book to loosen,y thus ensuring a maximum output of properly stitched books. o y

This object is attained by providing the throat plates through which the needles that form the tail stitches andthe hooks which form the chain or head stitches pass while stitching, with members movable transversely of the' needle paths, which following the stitching of the last signature of each book are shifted so that the threads ofthe tail stitches will bev loopedaround portions of the movable members and after several ofl the following signatures have been stitched will be drawn across knife edges of the movable member and severed. As several following signatures are stitched before the' threads of the tailv stitches are severed, when the books 1932. serial No. 625,352.

are separated the threads are drawn taut without pulling out thus obviating the necessity of forming an eXtra or locking stitch.

In the accompanying drawing Fig. l

shows a plan View of a throat plate which embodies the invention.

Fig. 2 shows a View of the under side of this plate.

Fig. 3 shows a transverse section of the supporting bar, throat plate and upper edges of some signatures, illustrating a loop ofthread formed over a section of the movable member of the throat plate.

Fig. 4 is a section looking from the front on the plane indicated by the dotted line 4-4 on Fig. 3, with the movable member of the throat plate in normal position, as when making the regular stitch. o

Fig. 5' is a front section on the same plane showing the movable throat member shifted sidewise so as to cause a thread to be wrapped around a part of it. Fig. 6 is an enlarged sectional view showing 4a thread loop wound about the movable throat member. t Fig. r('-is a plan view showing anumber of stitched signatures with the movable throat member indicated in several positions and the threads severed between the books, the upper portion of the ligure showing the'books before being separated, the intermediate section showingA a book partly separated and the threads as they are being pulled out, and the lower portion showing a book completely separated and the severed ends of the threads drawn out. y

The number of throat plates used in these machines depends upon the sizes of the books to be stitched and the' distance apart the lines o'f stitching are'to be spaced. A single throat fixed member has openings 6 for the passage of the needle 7 and perforations 8 for the passage of the looper hooks 9, and the movable member has openings 10 for the passage of the needles. The inner edges of the openings 10 in the movable vmembers are ground down to form knife edges 11. n A Y, y

The movable members of the throat plate arc fastened to aI shifting bar 12 by screws 13. The bar 12 is movable lengthwisekv in a groove in the under side of the supporting bar and is retained in the groove by the fixed member of the throat plates. Filling blocksl 14 are placed between the bar and the movable members, these blocks being movable in and guided by'slots 15 in the fixed throat member as the movable throat members are shifted. iAny suitable connection may be made between -the shifting bar and operating mechanism of the machine for reciprocating the bar and shiftf ing the movable members with relation tothe fixed members at the desired times. v

The needles and the hooks reciprocate v.as usual always in thesame paths. As the sidnatures are being stitched the needles which `formvthe straight-line or tail stitches pass through the'needle openings in the fixedmembers of the throat plates and also through one of the yopenings in the movable plates,'while the hooks which form` the chain or head stitches pass through hook perforations in the fixed members' only. On vthe start the movable members are in such position-thatjthe needles draw the threads through the openings 17 in the movableV members. Aften the last'signature of a Vbook'is stitched the connecting bar is moved so as to shift the movable members sidewise'and then while the needles pass through the same ope'ningin the fixed member they pass through the openings 18`in the movable members. This causes loops of thethread to bewound around the sections 19 that are between the openings throughl the movable members, as shown at the topfof Fig.' .7. After `the last signature of each book is stitched the movable members are shifted so as to loop the tail stitch threads, that is, the movable members are moved to one side and then-'back tothe other side, as indicatedin Fig. 7. The stitching continues and after several signatures have been stitchedv the backward movement of the stitched signatures causes thethreaded loops to be drawn across the knife edges of the openings through the movable' members andi be severed.j This is effected at such times that the threads are cut between the last signature ofV onefbook andthe first si gnature of the'following book, but lnot until several following signatures have been stitchechrso that thedrawing of the threadsV does not loosen the stitching, in fact,

' it tightens the stitching.v

' VWhen'abook is separated the'endsy 21 7, yof the cut tail stitchthreads are drawn from the tail stitchingthroughthe loops 22 of the chain stitching on the finished book, and then through the loops 23 of the chain stitching on the first signature of the following book. After one book is stitched and before the threads are .cut Yseveral signatures of the following book have been stitched so that in drawing out 'the threads the long ends of the threads remain in the loops of the chain and the books can be separated without loosening the stitching. A v

By the addition of the movable member to the commonly used fixed throat plate the tail stitches are surely looped after the last signature of eachbook is stitched, and are severed without loosening the stitches, and this is accomplished ,without interfering with the regular stitching or continuous feed of the signatures. f v

VThevinvention claimed is:` Y f1. Inra machine for stitching the folded edges of book signatures which has a throat kplate .with an opening for the passage of a needle and an 4opening for the passage of a hook, a needle that reciprocatesvertically throughthesaid needle opening, a hook that :reciprocates .vertically through fthe hook opening anda horizontally movable carrier adapted to rcarry'a thread loop from the needle'tovthe hook below. the throat plate, a memberattached to the throat plate and having a section .that moves at intervals .transversely acrossl the needle path in a; 'plane parallel with the line ybetween the needle opening and hook `opening andjdwells on one side of the needle ypath when the signatures of one book are being stitched. and then moves over and dwells on the other side ofthe needle path when the following book signatures are being stitched, whereby at the'finish of the stitching Vof the signatures of eachbook the needle thread will bejlooped over said section and after the feed of several following signatures will kbe drawn around said section to tighten the stitch and be severed.

2.-? In a machine for stitching the folded edges'of booksignatures which. has a throat plate with anopening for the passage of a needle and an opening for the passage of a hook, 'a needle that reciprocates vertically through the said needle opening, a hook that reciprccates vertically through the hookopening, and a horizontally movable Vcarrier adapted to carry a, thread loop from the needle to the hook fbelowqthe ythroat plate,` aY blade movable at intervals below the throat plate transversely' across the needle path in a plane parallel with thev line betweenthefneedle opening and hook opening and adaptedto dwell on one side Vof the kneedlelpath when the signatures of one book are being stitched andr to move over Vand! dwell on the Aother side of the needle path when the following book'signatures are being stitched, whereby at the finish of the stitching of the .signatures of each book the needle thread will bey looped over said blade and after the feed of several following signatures will be drawn around said blade to tighten the stitch and be severed.

3. In a machine for stitching the folded edges of book signatures which has a throat plate with an opening for the passage of a needle and an opening for the passage of a hook, a needle that reciprocates vertically through the needle opening, a hookV that reciprocates vertically through the hook opening and a horizontally movable carrier adapted to carry a thread loop from the needle to the hook below the throat plate, a member movable back and forth at intervals below the throat plate in a plane parallel with the line between the needle opening and hook opening, said member having an opening which registers with the needle opening in the throat plate when in one position and the signatures of one book are being stitched and an opening which registers with the nee- Adle opening in the throat plate when in its other position and the following book signatures are being stitched, whereby at the inish of the stitching of the signatures of each book the needle thread will be looped from one opening to the other opening of said member and after the feed of several following signatures will be drawn over the section between said opening to tighten the stitch and be severed.

4. In a machine for stitching the folded edges of book signatures which has a thro-at plate with an opening for the passage of a needle and an opening for the passage of a hook, a needle that reciprocates vertically through the said needle opening, a hook that reciprocates vertically through t-he hook opening and a horizontally movable carrier adapted to carry a thread loop from the needle to the hook below the throat plate, a cutter movable back and forth at intervals below the throat plate, transversely across the needle path in a plane parallel with the line between the needle opening and hook opening and adapted to dwell on one side of the needle path when'the signatures of one book are being stitched and to move over and dwell. on the other side of the needle path when the following book signatures are being stitched. v

5. In a machine for stitching the folded edges of book signatures which has a1 throat plate. with an opening for the passage of a needle and an opening for the passage of a hook, a. needle -that recip-rocates vertically through the said needle opening', a hook that rec-iprocates vertically through the hook opening and a horizontally movable carrier adapted to carry a thread loop from the needle to the hook below the throat plate, a member movable at intervals back and forth below the throat plate transversely across the needle path in a plane parallel with the line between the needle opening and hook opening said member having an opening with sharpened edges which registers with the needle opening in the throat plate when the signatures of one book are being stitched and an opening' with sharpened edges which registers with the needle opening in the throat plate when the following book signatures are being stitched.

6. In a machine for stitching the folded edges of book signatures which has a throat plate with an opening for the passage of a needle and an opening for the passage of a book, a needle that reciprocates vertically th fough tae needle opening, a hook that reciproca-tes vertically through the hook opening and a horizontally movable carrier adapted to carry a th read loop from the needle to the hook below the throat plate, a flat blade with'sharpened' rear edges attached to the under side of th-e throat plate and mov# able sidewise at intervals transversely across the needle path in a plane parallel with the line between the needle opening and hook opening and adapted to dwell on one side of the needle path when the signatures of one book are being stitched and dwell on the other side of the needle path when the following book signatures are being stitched.

7. In a machine for stitching the folded edges of book signatures which has a. throat -Y plate with an opening for the passage of a needle and an opening for the passage of a hook, a needle that reciprocates vertically through the needle opening, a hook that reciprocates vertically through the hook opening and a horizontally movable carrier adapted to carry a thread loop from the needle. to the hook below the throat plate, a member supported by and movable at intervals back and forth below the throat plat-e, transversely across the needle path ina plane Yparallel with the line between the needle opening and hook opening, said member having two openings 'that alternately register with the needle opening in the throat plate. CARL SCHRAMM. 

